1. Field of the Invention
The present invention relates to wall construction, and more particularly to a method and apparatus for anchoring wall mounted structures such as handrails and grab bars.
2. Description of Prior Art
Historically, the framework of a building wall was formed entirely of wood members, including wooden studs. In recent years at least in the United States, however, the use of metal studs has gained acceptance, especially in commercial buildings, such as office buildings and hospitals. It has been found that metal studs can be advantageously employed, since a suitable metal, such as galvanized steel, is stronger than wood, will not rot, is not subject to damage by pests such as termites, remains resistant to fire, and is economically feasible.
Metal studs are typically formed of sheet metal bent to encompass a cross sectional area having nominal dimensions of two inches by four inches. To conform to architectural plans and building code requirements, metal studs are formed of sheet metal bent into a generally U-shaped cross-section in which a relatively broad central base is flanked by a pair of narrower sides that are bent at right angles to the base. The base typically has a uniform nominal width of either four inches or 3⅝ inches, which is commonly referred to as the web. The sides of the U-shaped stud typically extends to a nominal distance of two inches from the base which are commonly referred to as flanges. To enhance structural rigidity to the flanges of the stud, the flanges are normally bent over into a plane parallel to and spaced from the plane of the web. These turned over edges of the sides thereby form marginal lips which are typically one quarter to one half inch in width. Conventionally, the metal studs are erected with the webs oriented on the same side in the same direction.
In building construction, there are certain situations which require the building studs to be braced or linked transversely to provide enhanced structural rigidity. The studs must be transversely bridged when they are over eight feet in length so that they provide adequate stability in a lateral direction within the wall which they support.
In certain instances, the metal studs require transverse backing between the studs in a building so to provide structural support against forces acting normal to or parallel to the plane of the wall assembly. For example, structural backing must be provided between adjacent parallel studs to provide necessary structural stability for the installation wall structures such as hand rails and grab bars most which conform to requirements of the Americans with Disabilities Act, i.e., withstand 250 pounds of point load pressure outward and downward parallel to the plane of the wall. A common way to provide backing is to shape pieces of plywood between adjacent studs and use screw fasteners to attach these pieces to adjacent studs. The number and placement of backing plywood pieces is determined by how much of the framework needs backing.
The use of fire-stops, bridging and backing in construction trade is well known in the prior art. Construction Codes and Fire Codes requires that these devices be positioned between metal studs to: (1) reinforce uniformly laterally spaced parallel metal studs; (2) discourage the spread of fire, smoke and gases within interior walls; and (3) anchor hand rails and grab bars to metal studs. Typically, sheetrock covers the studs and backing and is attached thereto.